1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) panel and manufacturing method thereof, and more particularly, to a transflective LCD panel and manufacturing method thereof.
2. Description of the Prior Art
LCD panels can be classified into transmissive, reflective, and transflective types based upon the source of illumination. Along with the popularization of portable electronic products, the LCDs have to give consideration to the brightness of indoor ambient light and that of outdoor ambient light, which are different greatly from each other. Therefore the transflective LCD panel is developed to provide superior performance in abovementioned different environments.
Please refer to FIG. 1, which is a schematic drawing of a conventional transflective LCD panel. As shown in FIG. 1, a transflective LCD panel 100 includes an array substrate 102, a color filter substrate 104 opposite to the array substrate 102, and a liquid crystal layer 106 sandwiched in between the array substrate 102 and the color filter substrate 104. The transflective LCD panel 100 also includes a plurality of pixel regions 110, and each pixel region 110 includes a reflection region 112 and a transmission region 114. The pixel regions 110 defined on the array substrate 102 respectively includes a thin film transistor (TFT) 120 and the TFT 120 is positioned in the reflection region 112 as shown in FIG. 1. In order to make optical path lengths of the transmitting light and the reflected light the same, the prior art further forms an organic insulating layer 130 covering the TFT 120 on the array substrate 102 in the reflection region 112 after forming the TFT 120. The organic insulating layer 130 is patterned to form a predetermined pattern by a photomask, then a reflective layer 132 is formed on the organic insulating layer 130. Because the predetermined pattern formed on the surface of the organic insulating layer 130, the reflective layer 132 formed along with the profile of the predetermined pattern obtains a rough surface. Consequently, reflectivity is improved. In the transmission region 114, a transparent pixel electrode 140 is formed and electrically connected to the TFT 120 through a contact hole 134 in the organic insulating layer 130.
As mentioned above, in order to make the optical path lengths of the transmitting light and the reflected light the same, the organic insulating layer 130 is provided in the transflective LCD panel 100 to raise the reflection region 112. Furthermore, a photomask is needed to define the position and the profile of the organic insulating layer 130. Accordingly, the organic insulating layer 130 is thickened to even a half of the cell gap. In other words, the formation of the organic insulating layer 130 unavoidably increases the process time and the process cost. It is noteworthy that as illustration denoted in circle 150, the height difference, which is caused by the organic insulating layer 130, in the border between the reflection region 112 and the transmission region 114 complicates the process control when forming the pixel electrode 140, even makes open line fault of the pixel electrode 140. In addition, to improve the reflectivity, the photomask is employed to form the predetermined pattern in the organic insulating layer 130 of the conventional transflective LCD panel 100, thus a rough surface is obtained after forming the reflective layer 132. Accordingly, it is conceivable that fabrication of a transflective LCD panel 100 is more complicated and more difficult in process control.